1. Technical Field of the Invention
The present invention relates generally to pressure sensors. More particularly, the invention relates to improved pressure sensors each of which has a compact size and high corrosion resistance and ensures high accuracy in sensing a pressure.
2. Description of the Related Art
Japanese Patent No. 3,198,779, an English equivalent of which is U.S. Pat. No. 5,595,939, discloses a pressure sensor that is configured to sense a pressure of a highly corrosive fluid.
According to the disclosure, the pressure sensor has a structure in which a sensing element is connected to connector pins by wire bonding, and all the sensing element, bonding wires, and connector pins are placed in an oil and sealed by means of a corrosive resistant metal diaphragm.
However, with such a structure, the pressure sensor necessarily includes the metal diaphragm, the oil, an O-ring for sealing, etc., thus resulting in great difficulty in making the pressure sensor compact.